A major portion of the art of paper making consists of sequential stages in which water is removed from a paper web. These various stages are differentiated by the different methods used to remove the water from the web. One such method is to provide a press fabric for contacting the web while the fabric and the web are passed through a high pressure region formed by a press nip. During this process water pressed out of the web is forced into and through the press fabric.
It has long been recognized that an ideal press fabric must be permeable to water, must resist compaction, and must maintain its dimensional stability. Although woven and non-woven fabrics have been suggested as press fabrics, improved results are continuously sought. An embodiment of a multilayer press fabric is described in U.S. Pat. No. 4,555,440, incorporated herein by reference.
Another aspect of useful press fabrics is that they can have a seam which allows faster, safer, and easier installation on a papermaking machine. Various methods of seam construction are known in the art, one advantageous arrangement of forming seams comprising a pin seam arrangement whereby machine direction loops in respective ends to be joined together are engaged by a cross-machine direction member. See, for example, U.S. Pat. Nos. 2,907,093, 3,281,905, 3,316,599, 4,250,822, 4,267,226, 4,344,209, and 4,601,785, all of which are incorporated herein by reference. Such seam arrangements have the disadvantages that they can cause marking of the paper sheet and that there may be loud popping noises when the seams pass over a suction box.